Lighting fixture with convoluted spring louvre



Sept. 29, 1959 A. o. BOUTELLE I 2,906,864

LIGHTING FIXTURE WITH CONVOLUTED SPRING LOUVRE Filed May 19, 1954 INVENTOR. 1444s 0. 50075445 LIGHTING FIXTURE WITH CONVOLUTED SPRING LOUVREAllen 0. Bontelle, Jefferson, Wis., assignor to Thomas Industries Inc.,Fort Atkinson, Wis., a corporation of Delaware Application May 19, 1954,Serial No. 430,758

2 Claims. (Cl. 240-4635) This invention relates to a convoluted springlouvre for lighting fixtures.

Both recessed fixtures and lamps have finish rings or plates ofcircular, square or other contour at the mouth of the lamp housing orreflector. In the past, louvres have been hinged, screwed, riveted, orotherwise fastened in place to bafile the light issuing from the lamp orfixture so as to confine the illumination to an area reasonably beneaththe fixture, while protecting from glare any observer outside of thatarea.

The present invention provides a convoluted spring louvre which can bemade in one piece in a form which, under compression, will fit theopening in the lamp housing to be retained frictionally therein, thenormal size and form of the louvre spring being greater than the crosssection of the mouth of the housing, so as to require the spring to becompressed for insertion or removal.

Such a louvre can be inserted or removed instantly and without tools toperform every function of a conventional louvre so far as bafiling isconcerned and, at the same time, to present an appearance moreornamental than that of conventional louvres.

In the drawings:

Fig. 1 is a view in perspective of a lamp housing in course of beingequipped with a louvre of my invention.

Fig. 2 is a plan view of the expanded louvre.

Fig. 3 is a bottom plan view of the assembled housing and the louvre.

The particular lamp housing shown constitutes no part of the presentinvention and is illustrated merely by way of exemplification of one ofthe numerous types of such housings with which the use of my springlouvre is appropriate. It will be understood that the mouth 4 of thehousing may be of any form in outline, the circular form illustratedbeing selected for exemplification because it is so commonly used. Ifmouth 4 has a non-circular outline, it is well within the skill of theart to modify the form of the spring louvre 5 to fit, in the light ofthe teachings of this disclosure.

In accordance with the present invention, a band 6 of spring stock ofany desired width is convoluted in any desired manner intermediate itsends to provide a spring louvre 5 which has an over-all dimension whichsubstantially exceeds that of the interior opening 4 of the lamp housingin which the louvre is to be used.

For a housing with a circular opening 4, I preferably provide theconvoluted spring strip 6 with arcuate ends at 7 and 8 of a radiussubstantially conforming to that of the mouth of the lamp housing sothat the terminal sections 7 and 8 may fit the lamp housing, in pressurecontact therewith, as shown in Fig. 3. In the embodiment illustrated,the louvre spring is symmetrical. At cor responding ends of the arcuateterminal ends 7 and 8 thereof, the spring strap is curved back uponitself at 9,

.United States Patent 0 10, leading to relatively straight sections 11,12 con- "ice 2 Curved portions 17, 18 are thus olfset beyond curvedsections 9 and 10. They lead to straight sections 19, 20 respectively,which are longer than straight sections 15, 16 so that the curvedportions of the strip shown at 21, 22 are olfset outwardly beyond curves13, 14. Curved sections 21, 22 lead to still longer straight sections23, 24, which are joined at the center of the spring by curve 25.

When such a spring louvre is subjected to compression, its over-alldimensions may readily be reduced to a size which will enable the springlouvre to be inserted into, or withdrawn from, the mouth of the lamphousing. When the spring is inserted, and the pressure relieved, thespring expands to the extent permitted by the dimensions of the lamphousing but remains under bias sufficient to retain it in position ofuse as shown in Fig. 3. In the compressed position of the spring thesections 11 and 15 are mutually convergent, sections 15 and 19 aremutually convergent, sections 19 and 23 are mutually convergent, and soforth.

I do not wish to be limited to any particular size or form of louvrespring, but, except as otherwise indicated in the accompanying claims, Iam directing this application for patent to a louvre comprising a springstrip having baflle portions positioned at intervals across the mouth ofa lamp housing or reflector and having an expanded outline which isnormally in excess of the outline of the housing mouth, whereby thespring must be compressed to fit within the housing mouth for use. Asabove explained, this result is achieved in practice for the type ofhousing illustrated by convoluting a strip of resilient material toprovide runs which extend to and fro to I span the housing mouth. If thehousing mouth increases in width toward the center as shown, thesuccessive convolutions or runs will desirably show a correspondingincrease in length from both ends of the spring toward the center.

I claim:

1. The combination of a louvre and a lamp housing having an open mouthof fixed dimension, said louvre comprising a single continuous strip ofspring stock having terminal portions normally separated more widelythan the interior of the housing mouth and extending thence to and froin laterally spaced convolutions and resiliently collapsible underpressure on such convolutions to reduce the space therebetweensufiiciently to permit the louvre to be introduced within the housingmouth and to span it from side to side, the said convolutionsconstituting baffle strips and forming baffle openings having a largeloop at one end and converging together at the other end and theresilient bias of said convolutions maintaining the louvre releasablyinplace.

2. The device of claim 1 in which the housing mouth is substantiallycircular and the convolutions of the strip have a maximum lengthadjacent a diameter thereof and progressively decrease in length towardsaid terminal portions.

References Cited in the file of this patent France May 24, 1932

